HONOLULU (KHON2) — On Monday, the Marine Mammal Center (MMC) announced that a male monk seal named RW22 died on Nov. 17, after battling with a parasitic disease known as toxoplasmosis over a five-week period.

MMC said RW22 was also suffering from the effects of ingested fishing gear and malnutrition.

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Toxoplasmosis is a complex and deadly disease that requires intensive daily treatment and management for an affected Hawaiian monk seal like RW22,” said Dr. Sophie Whoriskey, Hawaiian Monk Seal Conservation at The Marine Mammal Center. “All of us are deeply saddened about this unfortunate outcome but we find hope in knowing the valuable insights gained about how this deadly disease affects monk seals will have a positive impanct on future patients.”

According to MMC, for the past four weeks, RW22 was administered a series of intensive medical treatments to try to slow the rate of infection. RW22 regained some stamina and movement but continued to deteriorate due to weight loss from minimal eating.

MMC will conduct a post-mortem examination and will send tissue and blood samples to NOAA Fisheries for further examination.

The examination results could take weeks to months to process, according to MMC.

“Toxoplasmosis is the number one disease threat to the recovery of these endangered animals,” said Angela Amlin, Hawaiian Monk Seal Recovery Coordinator at NOAA fisheries. “The more partners and local communities can work to address this issue, the better for monk seals and other native species in Hawaii affected by this disease.”

MMC said with no vaccine available for toxoplasmosis, preventative measures must be taken by the general public. This disease is spread into the environment through cat feces.

One way to help monk seals survive is to throw away cat litter in the trash and keep cats indoors. According to MMC, Toxoplasmosis is one of the main threats facing the endangered Hawaiian monk seal population on the Main Hawaiian Islands, in part due to the infection being difficult to detect.

However, cats are not the only issue marine mammals face, MMC said other main threats to monk seals include negative human interaction and fisheries interaction through hooking and entanglements.

So far, three other seals impacted by this disease have been rescued prior to death and this is the second patient the Center has admitted to its Kona hospital with the disease, according to MMC.

For more information go to, Marine Mammal Center’s website.